Accumulator



Dec. 24, 1963 R. c. POSH 3,115,162

ACCUMULATOR 3 Sheets-Sheet 1 Filed July 16, 1959 INVENTOR. Fag mafia 6. 7 0.5%.

Dec. 24, 1963 R. c. PosH 3,115,162

ACCUMULATOR Filed July 16, 1959 3 Sheets-Sheet 2 Eli.

Dec. 24, 1963 R. c. POSH 3,115,162

ACCUMULATOR Filed July 16, 1959 3 Sheets-Sheet a 22 .IIIIIIIIIIIII 1 i 5 c E- /t l INVENTOR.

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United States Patent ()filice ant er Patented Dec. 24, 1963 3,115,162 ACCUMULATQR Raymond C. losh, Garden (Iity, Mich, assignor to American Metal Products Company, a corporation of Michigan Filed July 16, 1959, Ser. No. 827,588 12 Claims. (Cl. 133-345) This invention relates to accumulators and particularly to an accumulator in which a reserve supply of pressurized liquid is maintained.

Difficulty has been experienced in the past when constructing accumulators due to the presence of small apertures through which the fluid passes and a pressurized resilient rubber sleeve which applies pressure to the fluid. In the absence of the fluid, the pressure forces the sleeve toward the apertures and, when suificicnt pressure is present and the apertures are of sufiicient size, the rubber will pass into and sometimes through the aperture, and small areas will be sheared therefrom, perforating the sleeve. As a result, the apertures in the metal were made as small as possible to reduce the possibility of the rubber of the sleeve being damaged thereby, and to restrict the return flow of the fluid to thereby prevent the pulsation thereof when nonuniforrnly pressurized by a reciprocating pump. it has also been found difficult to seal the ends of the sleeve to the outer casing and to the caps applied to the ends thereof. Special sleeves were heretofore employed having end flanges which were much more expensive than lengths of tubing cut from a continuous length thereof.

It is one object of the invention to so construct the accumulator that the pressurized rubber sleeve will press against the walls of an element, which close the fluid passageways, to thereby positively prevent the rubber from moving into an aperture and to thereby permit an unlimited pressure to be applied to the rubber sleeve.

Other objects of the invention are: to provide an accumulator with a central pasageway enclosed by a rubber sleeve having a chamber thereabout containing a gas under pressure for applying a pressure on the fluid passing through the central aperture portion; to provide a rubber sleeve having its ends engaging the inner face of the outer casing of an accumulator and sealed therewith upon the expansion of the flanges of end caps which are secured in position by welding or by reverse flanging the end portions; to form an accumulator from a central element which is cross-shaped in section having end caps with cross-shaped slots thereon containing serrations on the inner face; to apply a four-fingered element to the ends of a central element which is cross-shaped in section and which, in unbiased position, provides passageways along the disposed cross-shaped element which are closed when the pressure on the rubber sleeve engages and forces the fingers against the element to prevent the rubber of the sleeve from moving into the passageways; and, in general, to provide an accumulator which is simple in construction, positive in operation and economical to manufacture.

Other objects and features of novelty of the invention will be specifically pointed out or will become apparent when referring, for a better understanding of the invention, to the following description taken in conjunction with the accompanying drawings wherein:

FIGURE 1 is a broken, sectional view in elevation of an accumulator embodying features of the present invention;

FIG. 2 is an enlarged sectional view of the upper lefthand end of the structure illustrated in FIG. 1, as viewed within the oval 2;

FIG. 3 is a view of structure, similarly illustrated in FIG. 2, showing another form thereof;

FIG. 4 is a view of structure, similar to that illustrated in FIG. 3, showing still another form of the invention;

FIG. 5 is a view of structure, similar to that illustrated in PEG. 4, showing another form which the invention may assume;

FIG. 6 is a sectional view of the structure illustrated in FIG. 5, taken on the line s s thereof;

FIG. 7 is a perspective view of the core portion of an accumulator embodying a further form of the invention;

FIG. 8 is a view of structure, similar to that illustrated in FIG. 7, with the end portions separable from the central portion;

FIG. 9 is a sectional view of the structure illustrated in FIG. 8, taken along the line 9'9 thereof;

PEG. 10 is an end view of a structure, similar to that illustrated in FIG. 8, showing a further form which the invention may assume;

PEG. 11 is a fragment ry view of a structure, similar to that illustrated in KG. 8, showing still another form which the invention may assume;

PEG. 12 is a broken sectional view of one end of an accumulator, showing a further form thereof;

FIG. 12A is a sectional view of the structure illustrated in FIG. 12, taken on the line 12-A12A thereof;

FIG. 13 is a sectional view of the structure illustrated in FIG. 12, taken on the line 13-13 thereof;

PEG. 14 is a view of the structure illustrated in FIG. 12, after pressure has moved the rubber sleeve inwardly, and

FIG. 15 is a sectional View of the structure illustrated in FIG. 14-, taken on the line l5-l5 thereof.

An accumulator i8 is illustrated in FIG. 1 as comprising an inner cylinder sleeve 19 having apertures there- 'thnough, a resilient rubber sleeve 21 surrounding the sleeve 19 and an outer sleeve 22 which surrounds the rubber sleeve 21. All of the elements may be cut from lengths of tubing and the inner sleeve 19 may be shaped to be ClOVBl'lBEf in section with a plurality of apertures extending along the inner portions thereof. fter the sleeve 21 is asseh bled on the sleeve 19 and the sleeve 22 is assembled on the sleeve 21, the sleeve 19* is expanded to compress the end of the sleeve 21 against the sleeve 22 and thereby secure it permanently in position. An end cap 23 is then forced within the outwardly offset portion of the inner sleeve 19, the cap and the ends of the sleeves '19 and 22 being secured together by the welding material 24 in a conventional manner.

Another manner of securing the sleeves l), 21 and 25 in unit sealed relation is illustrated in FIG. 3. In this arrangement a cap 26 is forced inwardly over an annular rubber band 2.7 after the sleeve 19 has been expanded against the end of the sleeve 21 to compress the sleeve against the outer sleeve 22. The annular flange 28 of the cap 2:;- is sealed by the rubber band 27 to the inner surface of the sleeve 19, the outer surface of which is sealed by the upper end of the sleeve 21 to the inner surface of the outer sleeve 25. The cap 26 has an outwardly extending flange 29 which limits the inward movement of the cap and over which the inwardly projecting flange 31 of the outer sleeve 25 is rolled and further rolled to extend at 32 inwundly within the cap 26. This firmly anchors the cap to the outer sleeve 22 with the olements in sealed relation to each other.

A further form of securing means is illustrated in FIG. 4 wherein the sleeve 19' is expanded against the sleeve 21 which is compressed against the end of an outer sleeve 33 which has an outwardly extending flange 34- at the end. A cap 35 engages the inner surface of the sleeve 19 and is sealed relative thereto by an O-ring 36 which is retained in position when an outwardly extending flange 37 of the cap 35 is rolled downwardly at 38 and inwardly 3 at 39 to securely lock the cap in position at each end of the device.

In FIGS. 5, 6 and 7, a further form of accumulator is illustrated comprising a central body portion 41 which is cross-shape in section having at the base of he arms 32, 4-3, 44 and passageways as which extend at through the end heads 47 into end recesses which slope outwardly to a thin annular edge 4-3. The rubber sleeve 21 is held against the outwardly curved edge 51 of an outer casing 52 when the cap 53 has its curved annular portion 54 moved into engagement therewith. Thereafter the laterally extending portion is flanged downwardly at 55 and rolled inwardly at 6'0 to secure the elements together in sealed relation. It will be noted that the sleeve 21 has been forced inwardly to surround the central core, and it will be noted that the rubber extend into the troughlike slots is without damage unless the pressure is sufficient to force a portion into the passageways 5d of the head 47. It is to be understood that all or" the caps 23, 2s, and 53 at each end of the devices have a threade bushing therein to permit the fluid to enter the accumulator at one end thereof and to pass therefrom at the opposite end through conduits which are threaded into the bushings.

In FIGS. 8 and 9, a further form of core 57 is illustrated that wherein a central body portion 53 is of uniform cross shape in section and may be an extrusion. As illustrated in FIG. 9, the core has four arms 42, 43, 44 and 45' thereon with separate end heads 59 applied at each end. The heads have cross-shaped apertures 61 therein with the inner surfaces provided with shallow corrugations to form passageways 62. The fluid passes through the bushing 56 or one end cap through the passageways 62 along the quadrants between the arms 42, 2-3, 44 and 4-5 causing the rubber sleeve to expand against the pressure on the outer side thereof. The fluid then passes throu h the apertures 62 of the opposite head 59 and out througl the bushing 56 on the opposite end of the accumulator.

A further form of the invention is illustrated in EEG. 10, that obtained by molding a body portion 58a to a pair of end heads 63. In this arrangement means are provided for producing a plurality of apertures 64 through the body of the head in the area aligned with the quadrants formed by the four arms of the body portion. Pins may be employed as inserts in the molds, or soluble material may be mixed with the resin of the head and dissolved therefromafter the molding operation to provide the passageways. It is to be understood that any of the cores of this invention may be made of a resin, a metal or any other material known to be suitable. When a resin material is employed for the central core having apertures in the end heads, as provided in F263. 7, 8 or 10, and the core is assembled with the rubber sleeve 21 and outer sleeve 22, a very inexpensive accumulator is provided which is very durable and substantially indestructible.

A further form of the invention is illustrated in FIG. ll, that wherein portions 65 of an end head 59]) extend into the quadrants between the arms 4-2, 4-3, and of the cross-shaped member 5%. Passageways 65 be tween the walls of the member 5817 and portions 65 are closed when the thin lip portions 67 are flattened when the rubber sleeve 23 is forced thereagainst. The thin lip portions prevent the rubber of the sleeve 21 from being forced into the apertures and damaged.

A still further form of the invention is illustrated in FIGS. 12 to 15, that wherein the central body portion 5c has end bushings 71 provided with a cylindrical end portion 72 which tapers to an annular edge forming a conical recess. The bushings 71 have crossed slots 4'?! therein forming four sections '73 which are sprung apart to form passageways 74 with the adjacent walls of the arms 42, 43, 44 and 45 of the body portion 58c. The sleeve 21 is sealed to the outer sleeve 33 and to the gr u annular portion '72 of the bushings ill when caps '75 are pressed into the recess within the annular portion 72 and rolled about the outwardly extending flange 34 of the sleeve 33. The caps have a threaded bushing 56 therein by which fluid is passed through the device from one to the other end thereof. A gas in the chamber 75 between the casing 33 and the rubber sleeve 21 is under a predetermined pressure which forces the sleeve toward the bushings 71 and the body portion title to apply the pressure to the iluid passing through the device. When the fluic is bled from the device, the pressure on tie sleeve 21 causes it to engage the four sections 73 and force them into engagement with the body portion title to mate accurately therewith when closing the passageways therebetween, as illustrated in FIGS. 14 and 15. irrespective of how much pressure is applied to the rubber sleeve 21, it will not become damaged, there are no apertures with which the rubber sleeve could contact or move into. it will be noted that the rubber sleeve is actually stretched when moved into the recess between the arms 42., d3, 44- and 45 without any detrimental effects, since there are no apertures into which the rubber could move.

Wh n pressure is again applied through the bushing at one end of the accumulator, the four sections 73 at that end will be forced apart to open the passageways along the walls of the quadrants of the body portion 53c and progressively expand the sleeve 21 as the liquid advances from the one end of the accumulator. Eventually the entire sleeve will be pushed back toward the sleeve 33 away from the sections 73 and the bushing 71 at the opposite end of the accumulator. The sleeve 21 acts on the outer ends of the sections '73 before moving from engagement therewith which, along with the resiliency of the material of the bushing, causes sections 73 to snap outwardly and open the passageways at the leaving end of the accumulator. The material of the bushings 71 is resilient so as to move the sections '73 to their extended position, as illustrated in FIG. 12, aided by the pressure of the sleeve 21 on the outer end of the sections and the leakage of oil beneath the inner ends thereof. To assist this resilient force of the bushing material, a coil spring 77 is employed between the bushing 5'6 and the base of the sections '73 about an extension of the bushing which locates the spring on the center line of the bushing. After the pressure of the chamber '76 collapses the sleeve 21 upon the withdrawal of the fluid from the accumulator, the sections 73 are forced into the quadrants of the body portion 580 at both ends of the accumulator. Fluid entering the righthand end of the accumulator will overcome the pressure exerted by the adjacent sections '73, the spring 77 and the resiliency of the material to force the sections apart. The sleeve 21 is progressively forced outwardly as the fluid passes to the left until it reaches the sections 73 at the left-hand end of the accumulator, forcing the sleeve 21 outwardly thereof to be spaced from the outer sleeve 33. The fluid will pass between the sections 73 and the walls of the quadrant from the slots 4% at the apices of the sections. The pressure exerted thereby will be greater than that on the outer surface, and the sections will be moved outwardly to open the passages, aided by the force of the spring and the resiliency of the material or" the sections, and thereby completely open the passageways 7d at the left-hand end or" the accumulator.

The fluid will pass through the bushing 56 at one end of the accumulator through passageways 74 along the surface of the central body portion 530, past the sections F3 into the interior of the sleeve 21. If the accumulator is functioning as a pressure dome closed at the end opposite to that having the bushing 56, the pressure will be maintained in the line connected to the bushing 56 and will dampen surges therein. Whether a bushing 56 is provided at one or both ends of the accumulator, the

pressure is available on the fluid trapped therewithin or passing therethrough.

Referring to FIGS. 1 and 3, a charging valve 81 is illustrated located in a flattened section 82 of the outer sleeve 22. The valve is made from a deformable material, metal, resin or the like, having a cylindrical body portion 83 extending through the wall portion 82. A head 84 on the inner end of the body portion 83 engages a sealing washer 85 and urges it against sealed relation with the inner surface of the wall portion 82. The outside end of the body portion 83 is flanged over at 86 in a manner which will not clamp the washer 85. The loose washer 85 will permit air or other gas to pass through an aperture S7 in the body into the interior of the casing 22 against the sleeve 21. The internal pressure acting on the head 84 will compress the washer of elastomeric material 85 against the surface of the outer sleeve portion 82 and the body 83 to seal the rubber passageway 87 and the space between the body portion 83 and the casing 22 to prevent the escape of the gas.

In any of the arrangements herein illustrated and described, the problem of sealing the inner and outer casings with the rubber sleeves therebetewen has been completely solved by the various modifications herein illustrated. The difficulty of providing apertures of a size to prevent the rubber of the sleeve from becoming damaged when forced thereagainst has likewise been solved. By molding the central core from resins or die cast materials, and by sealing the elements in the manner illustrated, inexpensive but durable accumulators have been provided.

What is claimed is:

1. In an accumulator: a central core structure of solid cross section; a resilient sleeve surrounding said core structure; an outer rigid casing surrounding said sleeve, peripheral end portions of said sleeve being compressed between outer peripheral end portions of said core structure and inner peripheral end portions of said casing; and a cap closing each end of said casing in sealed relation thereto, at least one of said caps having a passageway tlierethrough communicating with the outside of said core structure.

2. Apparatus as in claim 1 wherein said cap and said outer rigid casing are outwardly flanged, the outward flange of said cap being rolled over and under the casing flange throughout the circumference thereof.

3. Apparatus as in claim 1 wherein the passageway in each of said caps includes a circumierentially threaded portion.

4. Apparatus as in claim 1 wherein said core structure includes a central cross shaped portion having four arms forming four quadrants and head portions having crossed slots therein which extend over the ends of the arms, the inner faces of the slots being corrugated to form passageways with the walls of the quadrants.

5. Apparatus as in claim 1 wherein said core structure includes a central cross-shaped portion having four arms forming four quadrants and head portions having crossed slots therein which extend over the ends of the arms, the material between the slots being flexible and forming four sections having flexible lips which are pressed against the walls of the arms when engaged by the resilient sleeve.

6. Apparatus as in claim 1 wherein said core structure includes a central cross-shaped portion and cylindrical ends divided into four quadrants by said cross-shaped portion which forms passageways on the outside of the cross-shaped portion, the area of the quadrants in the cylindrical ends being provided with a plurality of apertures communicating with said quadrant passageways.

7. In an accumulator, a central core of solid crosssection having a plurality of extending arms forming passageways therebetween on the outside of said core, end elements having slots therein for receiving the arms of the core, the slots dividing said elements into a plurality of fingers which extend within said passageways when placed over the ends of the core, said fingers being sprung apart by tension means, a resilient sleeve about the arms and end elements, an outer casing surrounding said sleeve, a cap at each end of the casing sealed therewith and with the sleeve and the end elements, and a hollow bushing in at least one of said caps which conducts fluid through the openings between said fingers and the walls of said arms.

8. In an accumulator, a central core of solid cross section having a plurality of extending arms forming passageways therebetween on the outside of said core, end elements having slots therein for receiving the arms of the core, the slots dividing said elements into a plurality of fingers which extend within said passageways when placed over the ends of the core, said fingers being sprung apart by tension means, a resilient sleeve about the arms and end elements, an outer casing surrounding said sleeve, a cap at each end of the casing sealed therewith and with the sleeve and the end elements, and a hollow bushing in at least one of said caps which conducts fluid through the openings between said fingers and the walls of said arms, said openings being closed when the resilient sleeve moves into engagement with the end elements and the arms when the fluid is no longer present within the sleeve, forcing the fingers into intimate contact with the walls of the arms.

9. In m accumulator, a central core of solid cross section having a plurality of extending arms forming passageways therebetween on the outside of said core, end elements having slots therein for receiving the arms of the core, the slots dividing said elements into a plurality of fingers which extend within said passageways when placed over the ends of the core, said fingers being sprung apart by tension means, a resilient sleeve about the arms and end elements, an outer casing surrounding said sleeve, a cap at each end of the casing sealed therewith and with the sleeve and the end elements, and a hollow bushing in at least one of said caps which conducts fluid through the openings between said fingers and the walls of said arms, said tension means being provided in the material of the fingers.

10. In an accumulator, a central core of solid cross section having a plurality of extending arms forming passageways therebetween on the outside of said core, end elements having slots therein for receiving the arms of the core, the slots dividing said elements into a plurality of fingers which extend within said passageways when placed over the ends of the core, said fingers being sprung apart by tension means, a resilient sleeve about the arms and end elements, an outer casing surrounding said sleeve, a cap at each end of the casing sealed therewith and with the sleeve and the end elements, and a hollow bushing in at least one of said caps which conducts fluid through the openings between said fingers and the walls of said arms, said tension means being provided by a spring located at the base of the fingers.

11. In an accumulator, a central core member of solid cross section and end elements having openings through which a fluid may pass, a rubberlike sleeve disposed over said member and elements, a casing enclosing said sleeve, and means sealing the ends of said elements, sleeve and easing together so that a compressible material may be provided between the sleeve and easing which exerts pressure on a fluid as it passes through one element and out the other over the outside of said core member and acts upon portions of said elements to cause them to deflect and close the openings when no fluid is present within the sleeve.

12. In an accumulator, a central core member of solid cross section and cylindrical end elements having openings through which a fluid may pass, a rubberlike sleeve disposed over said member and elements, a rigid casing enclosing said sleeve and sealing it to the cylindrical wall of the end elements by compressing it thereagainst, a cap closing each end of said casing in sealed relation thereto,

References Cied in the file of this patent UNITED STATES PATENTS 2,766,765 Belanowski et a1 Oct. 16, 1956 2,769,457 Wittenberg Nov. 6, 1956 2,789,577 Hosking Apr. 23, 1957 10 8 Di Mattia et a1 Iune 10,1958 Bent Jan. 6, 1959 Pier Mar. 3, 1959 Sherer-et a1. Sept. 1, 1959 Di Mattia--eta1. Oct. 13, 1959 Mercier Apr. 12, 1960 Leifier Oct. 17, 1961 FOREIGN PATENTS Great Britain Oct. 18, 1934 {Paw/k UNITED STATES PATENT OFFICE CERTIIFICATE OF CORRECTIGN December 24 1963 Patent No. $115,162

Raymond C.. Posh It is hereby certified that error appears in the above numbered patd as ent requiring correction and that the said Letters Patent should rea corrected below Column 8, line 7, for "3,004,650" read 3,004.560

Signed and sealed this 28th day of April 1964.

(SEAL) Atte'et: ERNEST W, SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. IN AN ACCUMULATOR: A CENTRAL CORE STRUCTURE OF SOLID CROSS SECTION; A RESILIENT SLEEVE SURROUNDING SAID CORE STRUCTURE; AN OUTER RIGID CASING SURROUNDING SAID SLEEVE, PERIPHERAL END PORTIONS OF SAID SLEEVE BEING COMPRESSED BETWEEN OUTER PERIPHERAL END PORTIONS OF SAID CORE STRUCTURE AND INNER PERIPHERAL END PORTIONS OF SAID CASING; AND A CAP CLOSING EACH END OF SAID CASING IN SEALED RELATION THERETO, AT LEAST ONE OF SAID CAPS HAVING A PASSAGEWAY THERETHROUGH COMMUNICATING WITH THE OUTSIDE OF SAID CORE STRUCTURE. 